The medical journal the Lancet highlights Wednesday cases of three Austrian men who received successfully, between April 2011 and May 2014, the technique developed by Professor Oskar Aszmann of the University of Vienna who has developed a hand Bionic controlled by the brain providing benefits comparable to those of a transplant, and to ensure many manipulations of everyday life.

The first known example was a 21 year old Lithuanian born with a birth defect, whose Aszmann professor replaced the end of 2014 the inert arm robotic prosthesis. The three patients cited by the British magazine have been themselves victims of serious accidents that damaged their brachial plexus, a network of nerves located in the neck and controls the movement of the upper limbs.

The injuries of the brachial plexus represent a kind of internal amputation, cutting irreversibly link between the nervous system and the member. The rebuild process bionic implies that the patient previously accepted amputation of the hand.

According to Professor Aszmann, bionics reconstruction is less risky than hand transplant practiced since 1997, which requires the taking of powerful immunosuppressive drugs, and sometimes results in the need to re-amputate the patient.

No side effects

“In the case of the loss of one hand, I think the bionic reconstruction more benefits because it has no side effects and that the quality of the recovered function is almost as good as a transplant, “says the Austrian surgeon told AFP.

“There is no sensitivity, it is not flesh and blood but the plastic and components. But the functional point of view, it is comparable to the transplant. ”

The major achievement of the Viennese team is to have recreated a complete neurological transmission signal to the bionic hand.

The latter is equipped with sensors that respond to the electrical pulses supplied by the muscles.

To do this, the teacher Aszmann grafted in the forearm muscles of patients collected within their thighs, then grafted nerve from another area of ​​the spinal cord as the brachial plexus.

“The hand is very far from the brain,” says the doctor, “This is more than a meter in nerve regeneration. The second difficulty is that the hand itself needs a lot of signals from the nerves to do what she can do. ”

Prior to amputation, patients undergo cognitive training for several months, first by controlling a virtual hand shown on video and then acting on a hybrid hand attached to their real hand.

“Some patients at the end of the process, can not be candidates for the bionic reconstruction,” says Oskar Aszmann, either because they do not have sufficient available nerves, either because they are not ready psychologically , or even lack of a suitable environment “, that is to say, the ability to maintain their prosthesis where they live.